Warning: Spoilers Ahead
Unfortunately, Merle knew Rick wouldn't follow thru with it, and took matters into his own "hand", tying up Michonne and heading toward the Governor.
But guess what? It turns out that deep underneath that gritty, racist exterior is a heart of gold, as he not only let Michonne go, but he led a brilliant offensive against the Governor and his men who were waiting to kill Rick.
Using a hot-wired car, he led a group of walkers right to the meeting location (pied piper style), set himself up inside a building, and once the Governor's men started firing at the walkers, he started firing at THEM! The beauty is that with all the gun fire, no one suspected that anyone was shooting at them... that is, until Merle (while aiming at the Governor himself) accidentally shot young Ben, the teenage boy member of Tyreese's group. To make matters worse, Merle was attacked by a walker and in killing it, was exposed to the group.
And then the poop hit the fan.
The Governor and his men beat the crap out of Merle as he tried to fight back. And finally, Merle suffered the ultimate fate... the Governor shot him in the chest and killed him.
Sometime later, after the area was clear, Daryl (who set off after Merle) finds him eating flesh as a walker, and has to put him down.
It was actually very sad and emotional as Merle's last act of heroism 'saved his soul' in the eyes of the viewers.
Here's a look behind the scenes of that episode and interviews with the actors.
Aim high. Run fast. Goodbye Merle.
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